Channelized model observer using a visual discrimination model

Jeffrey P. Johnson, Jeffrey Lubin, John S. Nafziger, Elizabeth A. Krupinski, Hans Roehrig

Research output: Contribution to journalConference articlepeer-review

8 Scopus citations


Previous studies in which the JNDmetrix visual discrimination model (VDM) was applied to predict effects of image display and processing factors on lesion detectability have shown promising results for mammographic images with microcalcification clusters. In those studies, just-noticeable-difference (JND) metrics were computed for signal-present and signal-absent image pairs with the same background. When this "paired discriminability" method was applied to Gaussian signals in 1/f 3 filtered noise, however, it was unable to predict detection thresholds measured in 2AFC trials for different backgrounds. We suggested previously (SPIE 2002) that a statistical model observer using channel responses from "single-ended" VDM simulations could predict detection performance with different backgrounds. The implementation and evaluation of that VDM-channelized model observer is described in this paper. Model performance was computed for sets of signal and noise images from two observer performance studies involving the detection of simulated or real breast masses. For the first study, the VDM-channelized model observer was able to predict the dependence of detection thresholds on signal size (contrast-detail slope) for 2AFC detection of Gaussian signals on different 1/f 3 noise backgrounds. Variations in the detectability of masses in mammograms from the second study correlated well with model performance as a function of display type (LCD vs. CRT) and viewing angle (on-axis vs. 45° off-axis). The performance of the VDM-channelized model observer was superior to results obtained using either the VDM paired discriminability method or a conventional nonprewhitening model observer.

Original languageEnglish (US)
Article number24
Pages (from-to)199-210
Number of pages12
JournalProgress in Biomedical Optics and Imaging - Proceedings of SPIE
StatePublished - 2005
EventMedical Imaging 2005 - Image Perception, Observer Performance, and Technology Assessment - San Diego, CA, United States
Duration: Feb 15 2005Feb 17 2005


  • Channelized model observer
  • JNDmetrix
  • Mammography
  • Observer performance
  • Visual discrimination model

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Channelized model observer using a visual discrimination model'. Together they form a unique fingerprint.

Cite this